Tennys Sandgren, the last remaining American in the Australian Open men’s singles draw, has deleted years-worth of tweets after denying he is an alt-right sympathiser.

The 26-year-old reached the quarter-finals of the tournament after an upset victory over the No5 seed, Dominic Thiem, on Monday but questions over his political views had swirled over the weekend and he was challenged at a post-match press conference.

Tennys Sandgren (@TennysSandgren)

everything.. It's sickening and the collective evidence is too much to ignore

Sandgren was challenged over his views by a reporter after his victory over Thiem. “Look, who you follow on Twitter I feel doesn’t matter even a little bit,” he said. “What information you see doesn’t dictate what you think or believe. I think it’s crazy to think that. I think it’s crazy to assume that. To say, well, he’s following X person, so he believes all the things that this person believes, I think it’s ridiculous. I think that’s ridiculous.”

Sandgren has also debated racial injustice in America with fellow tennis player James Blake on Twitter. During the exchange he denied systemic racism exists in the US because the country elected a black president.

Tennys Sandgren (@TennysSandgren)

I just don't know how a country that practices systematic racism elected a black pres, twice

The world No97 also denied he supported far-right theories. “No. No, I don’t. I find some of the content interesting, but no I don’t. Not at all,” Sandgren said. “As a firm Christian, I don’t support things like that. I support Christ and following Him and that’s what I support.”